The invention relates to a high-speed generator drive for matching the rotation speed of a gas turbine to an electricity generator.
It is generally known for a two-stage epicyclic gear to be arranged between the output driveshaft from a gas turbine and an electricity generator, in order to reduce the high output speed of the gas turbine and to match it to the electricity generator.
For this purpose, two epicyclic gear stages are arranged one behind the other and are connected to one another by a coupling. The planet gears are in this case mounted in a planet support, either on both sides in the form of a cage or, for low power levels, also such that they are floating.
Reduced epicyclic gears, as they are referred to, which manage with a reduced number of elements, are also known. A sun wheel in this case engages in planet gears on each of whose shafts a further planet gear is arranged axially offset, and these together form a further planet set, which engages with an annular gear. The planet supports of the two epicyclic gear sets are each designed in the form of cages and are assembled to form a common web. This expensive, two-element configuration, which is complicated to assemble, is required in order to allow the tooth engagement forces of the planet gears in the annular gear to be supported via the bearings which are mounted in the planet support. This configuration also makes it harder to service the drive system.
Against this background, the object of the present invention is to provide a two-stage epicyclic gear which has a simple design, is easy to install and in which the system is easy to service.
The particularly advantageous arrangement according to the invention allows the gearwheels in the two epicyclic gear sets to be preinstalled on a common shaft and the tooth edges can simply be aligned with one another in an assembly apparatus, so that the complex adjustment process during assembly is avoided. This allows the drive to be installed particularly easily and without any complications.
The arrangement according to the invention allows the moments of the circumferential forces of the two epicyclic gear sets about the center bearing to be matched to one another. As a result, only a small bearing, to absorb the radial forces, now needs to be provided on the planet gear shafts.
The particularly advantageous design according to the invention simplifies in particular the installation, maintenance, stockholdings and replacement of essentially simple standardized parts and completely preassembled units.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.